1. Field of the Invention
The present invention relates to a height adjusting mechanism for a tape guide, and more particularly to a height adjusting mechanism for a tape guide which adjusts the height position of a tape guide pin that guides running of a VCR cassette tape.
2. Description of the Related Art
In a recording and reproducing apparatus such as a VCR (Video Cassette Recorder), a tape guide pin is disposed in order to guide running of a magnetic tape and also to regulate the height position of the running magnetic tape. The tape guide pin is supported by one end of a tape guide arm. A tape guide arm is described in, for example, JP-A-2-227859, JP-A-4-315852, and JP-A-2000-30232. Usually, a swing shaft that protrudes downwardly from the tape guide arm is attached to a chassis in a swingable and vertically movable manner.
Conventionally, in order to position the height position of the tape guide pin during a process of assembling a VCR, a height adjusting screw is screwed into another end portion of the tape guide arm, and the tip end of the height adjusting screw is passed through the tape guide arm to butt against the chassis. In order to prevent the screw from loosening, a spring is interposed between the tape guide arm and a head portion of the screw so as to always apply tension between the screw and the tape guide arm. By rotating the height adjusting screw, the distance between the tip end of the screw (i.e., the upper face of the chassis) and the tape guide arm is adjusted to vertically move the tape guide arm, thereby adjusting the height position of the tape guide pin that is supported by the one end of the tape guide arm.
As described above, the tape guide arm is attached so as to be vertically movable with respect to the chassis. In order to prevent the tape guide arm from slipping out from the chassis, a washer is disposed on the tip end of the swing shaft that protrudes downwardly below the chassis.
In the conventional height adjusting mechanism for a tape guide pin, the spring is necessary for preventing the height adjusting screw from loosening. Moreover, a process of forming a screw hole is required for allowing the tape guide arm to be smoothly vertically moved. Since the swing shaft and the tape guide arm are integrally vertically moved, the washer should be disposed on the tip end of the swing shaft for preventing them from slipping out from the chassis, and a process for attaching the washer is necessary. Therefore, the mechanism requires a large number of parts, and an increased number of processes. Moreover, many assembling steps must be additionally conducted in order to attach the spring and the washer, and the assembling processes are cumbersome, thereby causing a problem in that the assembling cost is high.